The PV Watts gives ambient temperature and wind speed data in the hourly CSV output, and I just created a formula to calculate available wind energy for the given wind speed and turbine efficiency. The microhydro was just a basic reserve calculation on my elevation change, reservoir volumes, and average monthly rainfall; my intent was to try and use it as a dump load as well, but it wasn't effective.
The project included a greenhouse, desalinization system, and I was cooling a thermal mass during the afternoon when I had available power. The desalinization system could run for 3 hours and generate 24 hours of water consumption, not 3 hours at peak load.
How many days are you planning for a battery? I found I didn't have many discretionary loads that could be deferred for more than 3 days which drove storage substantially when I wanted to limit generator run time; I needed it 80+ days per year with a 3-day battery.
There are likely some math errors on demand side (especially looking at installed HP for some motors rather than going to the trouble to calculate BHP), but the general results seem rational.
...out of some 5+ billion that have walked through US airport security checkpoints since. Out of (pessimistically) 50,000 people with the will or propensity to inflict ill will via items contained on their person or in their luggage on others. (And arguably 5 that could be successful on a given trip.)...At a cost of countless millions of wasted hours, billions of wasted dollars, and fundamentally liberty lost.
I modeled a quad-gen system with 4kW PV on 2-axis trackers, a 3kW wind turbine, 1kW micro-hydro, and a 2kW genset. Annual energy consumption was 7.5MWh. Batteries were sized at 25kWh; the micro-hydro could do 20kWh storage. I had some substantial demand-side flexibility due to a RO system that was sized to handle peak demand with 3 hours of operation per day, thermal storage, and a few other tricks. Peak demand was 5kW.
The PV System produced 86% of the needed power, and wind 12%. The micro-hydro was primarily backup, and was adequate for all but 6 hours per year when the generator was required. In practical use the generator would likely need to operate more when other components were out of service.
The point of this is that I needed 2x capacity vs peak demand, and 11x for average demand, even with tremendous flexibility in demand-side control. While the wind saves a few cycles on the battery per year, at least two thirds of the energy produced would be burnt up by the load dump. The microhydro was a waste and would never justify the cost; likely much more environmentally friendly to just get another generator.
The lowest capital cost solution for me would be a 6kW PV Tracker and a 65kWh battery, along with the 2kW genset, but I would be generating 30% more power than I could use most days. Running the numbers isn't that hard; even taking grid stability issues out of the equation it is clear that you are stuck with a substantial energy storage issue, either in the form of thermal or chemical.
I would suggest taking a look at the 8760-hour output of the NREL PV Watts program; it is enlightening. For me, if I sized a PV array at 150% capacity (best-day production vs average demand), I would need 80 hours of generator backup per year if my battery were sized for 3-days demand. If I have 7-days, I would only need a generator for 4 hours per year of generator.
The bottom line is that you need substantial excess capacity and a huge geographic diversity to be able to get by on renewables alone. Think 400% or so. That is incredibly inefficient.
The cable connection at the lightning connector has failed on me several times, specifically because the connector stays connected to the device. The removal force exceeds the strength of the cable. Yes, I understand you shouldn't pull from the cable, but the connector body is sometimes too small to get a good hold on.
As an Apple customer, I am quite happy they ditched the "30-pin" connector and went with the reversible lightning connector. One less thing to fiddle with when charging my phone. Nice to see USB picking up the feature, even if it is a couple years later with implementations still not available.
That said, the cable/connector interface on the lightning cables is not nearly strong enough for the insertion/removal force required. It will be interesting to see if the USB design will work better in that regard, as the shield does provide some mechanical latching.
Use speaker phone. Once you are on speaker, there is no assumption of privacy. Once there is no assumption of privacy, then you can record... at least in California.
Not just documentation about the automation, but also making sure that the original mind-numbing manual process is properly documented! I would also say there should be an intermediate level of documentation between the manual process and the automated process indicating how it ideally should work.
When today's needs change, having the path to work back to how the original came to be is critical.
CO2 causes acidification of the oceans, which is a much bigger problem than the greenhouse effect, and will happen much sooner than the point where atmospheric CO2 levels become toxic to humans.
Some people are bad with money and make stupid life decisions. No wage or training will fix it.
My office manager makes almost $75k, and financed a used car at 19% interest, even after I explained how to calculate the interest to her. She is 40 and a grandma. She gets a bonus and uses it to buy seasons pass at a theme park. I think a few country songs were written about her....
That actually isn't true. Bringing action against an employer is easy and free for the employee, and the penalties are severe. What the current system does is encourage employers to make their employees live in fear so they will be too intimidated to file an action-- battered wife syndrome essentially.
No clue how to improve it, but right now an honest, good faith mistake could bankrupt a company.
There are plenty of citizens who are afraid of reporting abuses. There are no simple solutions; the reality is that employers need to act ethically and morally in their treatment of employees. (Good luck with that.) Reality is that people take the easy way out and make decisions on short term outcomes only.
Raising the minimum wage hurts me as an employer, despite the fact that we don't pay anyone less than twice (California) minimum wage. The issue for us in making sure we can classify engineers as exempt (salaried) employees. Only employees at over twice the minimum wage are eligible to be exempt status, and it would mean that some entry-level engineers would need to be classified as non-exempt. This brings in the mandatory breaks, lunches, and workplace rules that are inappropriate for a professional environment.
Sure, you can say pay them more, but that really doesn't solve the problem; it just makes it unattractive to hire people that aren't stars. We can have some engineers that are mediocre; not all tasks need stars. Hopefully we can turn them into stars in time, but that requires some discount in pay to be attractive.
You have obviously never dealt with copier maintenance. You can make it break whenever you want; there is even a scheduling routine built into the system for the technicians. The only reason to sell the toilet will be the service contract...
Reverse power flow at the primary substation level is an issue, but even moreso is the idea that you push 4x the current during peak generating periods that you would normally consume.
To make distributed generation work you need: distributed energy storage; capacity-responsive demand; or a high level of diversity in sources. It is difficult to get the diversity with solar except in partly cloudy conditions during the day, and the economics of small wind turbines are difficult to reconcile.
It is hard for me to imagine how nuclear provides compatibility with renewable; the compatibility always comes in the form of energy storage which smooths out the load profile. The best use-case is to have enough batteries to supply your loads from late afternoon through bedtime, and switch to utility to bridge through the night, maybe with a little small-scale wind thrown in at night.
Most people under 50 today will have 40+ year working careers. Do you really want 20-30 different employers over that time?
My personal experience is everyone has a different timer inside, and tends to change jobs on 1.5-2 year, 4-5 year, or 7-10+ year cycles. It is hard for people to break those cycles. Shorter cycles tend to be more performance-based; getting caught over-selling capabilities, and longer cycles are more complacency. People that do project-based work are a little different in rationale, but same kind of timers.
My advice is generally to leave a bad work environment quickly, but try to improve the work environment first before giving up.
As an employer, I avoid people that jump around because it is too expensive to recruit, train, bring people up to speed, and phase them out. If I don't think someone will be around for at least 3 years then they face an uphill battle.
Best way of managing those issues I have seen is to project on a whiteboard, markup there, while someone independent is marking up the PDF files electronically. When the discussion is finished, project up the markup PDF.
I agree with the parent's general process, but I do have meetings each week myself with 30 attendees and quite literally a ream of paper printed for each person. The actual drawings aren't re-printed for each meeting, but an updated 75-page schedule, 150-page RFI log, and 200-page submittal log is provided to each attendee, along with about 25 pages of meeting minutes and current issues.
It is hard to have a more efficient set-up, as the meeting is basically a coordination meeting for 5 different paper-pushers from different companies. Paper quickly becomes the lowest-common denominator. (Really pissing me off is the fact that the three people from my company all need to scan the documents afterwards to pick up their individual notes!)
If I was running the meeting, I would require a 2-page summary from each paper-pusher on open items, and have a projector that can be used to provide additional information when needed. Distribute the whole package electronically before the meeting and let people figure out how the heck they want to deal with the information themselves.
Not sure if the math is as favorable if you look at the net present value of the incremental earnings. Looking at individuals though, if you are bottom quintile you might be able to get a job that isn't manual labor, arguably improving quality of life. Being a tradesman though likely pays off better.
An entry level candidate in my field of engineering should have a solid foundation from their BS to be able to understand basic theory and concepts. Our job is to train them from that foundation in our specific field; there are fewer than 500 people a year who graduate with sufficient education to really hit the ground running.
They should have also passed the first test in the Professional Engineering process which gives them a head start in their career.
Does anybody else think it is ironic that they use the total earnings rather than the NPV at age 18 for the discussion on STEM earnings?! The bottom line is likely that the marginal increase in earnings is likely insufficient to justify college attendance for the lower quintiles if you have to pay your own way vial loans.
As long as the purchaser was looking at the ratio of NPV of the future Bitcoin earnings to the cost to purchase and operate in $ to justify his purchase then there is no problem with asking for a refund. The exchange risk on the ratio of Bitcoin to USD is all on the buyer though.
What percentage of people use Netflix 24x7? How many different shows do most Netflix users watch? Caching 48-72 hours of entertainment during periods of low utilization makes the situation better for everyone. Think of it as demand-leveling.
It is all peak-period problems, not average bandwidth. Invariably we get downgraded to barely viewable overcompressed SD on Sunday nights. A local smart cache of the next 5 episodes of the 5-6 different shows we watch most often would likely eliminate 90% of the network usage. If enough people have them it would make it a non-issue for the telco.
It is important for it to be a network-based cache though, so it is device independent.
Not really. Consumer class service has traditionally had a contention ratio of 20:1, while Business class service is closer to 5:1. If you have a 20Mb link, you should be entitled to 1Mb minimum. You aren't restricted by the last mile, but the overall network today.
The issue comes down to contention ratios and peering. The last-mile ISPs don't want to peer with Netflix at a Hub level, they want to peer at a POP level, so they don't "waste" any of their backbone network between carrying Neflix traffic. Both parties are acting in their own self-interest.
Rationally, I have to think that when one service provider represents 10% or more of the traffic on a given network they should be doing something to address it, and the responsibility really falls on their shoulders and not the ISP.
Using Netflix as a simple example, all they would need to do to reduce their problem is offer a cache option on the end-user's network. It is less efficient than having it at the ISP's facilities, but it isn't all that complicated and the cost can be borne by the customer and improve sticky-ness. Right now, it is a pain in the ass to do things like a proxy to avoid the network saturation.
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The PV Watts gives ambient temperature and wind speed data in the hourly CSV output, and I just created a formula to calculate available wind energy for the given wind speed and turbine efficiency. The microhydro was just a basic reserve calculation on my elevation change, reservoir volumes, and average monthly rainfall; my intent was to try and use it as a dump load as well, but it wasn't effective.
The project included a greenhouse, desalinization system, and I was cooling a thermal mass during the afternoon when I had available power. The desalinization system could run for 3 hours and generate 24 hours of water consumption, not 3 hours at peak load.
How many days are you planning for a battery? I found I didn't have many discretionary loads that could be deferred for more than 3 days which drove storage substantially when I wanted to limit generator run time; I needed it 80+ days per year with a 3-day battery.
There are likely some math errors on demand side (especially looking at installed HP for some motors rather than going to the trouble to calculate BHP), but the general results seem rational.
Pretty good for the contractors though...
I modeled a quad-gen system with 4kW PV on 2-axis trackers, a 3kW wind turbine, 1kW micro-hydro, and a 2kW genset. Annual energy consumption was 7.5MWh. Batteries were sized at 25kWh; the micro-hydro could do 20kWh storage. I had some substantial demand-side flexibility due to a RO system that was sized to handle peak demand with 3 hours of operation per day, thermal storage, and a few other tricks. Peak demand was 5kW.
The PV System produced 86% of the needed power, and wind 12%. The micro-hydro was primarily backup, and was adequate for all but 6 hours per year when the generator was required. In practical use the generator would likely need to operate more when other components were out of service.
The point of this is that I needed 2x capacity vs peak demand, and 11x for average demand, even with tremendous flexibility in demand-side control. While the wind saves a few cycles on the battery per year, at least two thirds of the energy produced would be burnt up by the load dump. The microhydro was a waste and would never justify the cost; likely much more environmentally friendly to just get another generator.
The lowest capital cost solution for me would be a 6kW PV Tracker and a 65kWh battery, along with the 2kW genset, but I would be generating 30% more power than I could use most days. Running the numbers isn't that hard; even taking grid stability issues out of the equation it is clear that you are stuck with a substantial energy storage issue, either in the form of thermal or chemical.
I would suggest taking a look at the 8760-hour output of the NREL PV Watts program; it is enlightening. For me, if I sized a PV array at 150% capacity (best-day production vs average demand), I would need 80 hours of generator backup per year if my battery were sized for 3-days demand. If I have 7-days, I would only need a generator for 4 hours per year of generator.
The bottom line is that you need substantial excess capacity and a huge geographic diversity to be able to get by on renewables alone. Think 400% or so. That is incredibly inefficient.
The cable connection at the lightning connector has failed on me several times, specifically because the connector stays connected to the device. The removal force exceeds the strength of the cable. Yes, I understand you shouldn't pull from the cable, but the connector body is sometimes too small to get a good hold on.
As an Apple customer, I am quite happy they ditched the "30-pin" connector and went with the reversible lightning connector. One less thing to fiddle with when charging my phone. Nice to see USB picking up the feature, even if it is a couple years later with implementations still not available.
That said, the cable/connector interface on the lightning cables is not nearly strong enough for the insertion/removal force required. It will be interesting to see if the USB design will work better in that regard, as the shield does provide some mechanical latching.
Use speaker phone. Once you are on speaker, there is no assumption of privacy. Once there is no assumption of privacy, then you can record... at least in California.
Not just documentation about the automation, but also making sure that the original mind-numbing manual process is properly documented! I would also say there should be an intermediate level of documentation between the manual process and the automated process indicating how it ideally should work.
When today's needs change, having the path to work back to how the original came to be is critical.
For reference, a big excavator today for mining can go over 40 cubic meters
CO2 causes acidification of the oceans, which is a much bigger problem than the greenhouse effect, and will happen much sooner than the point where atmospheric CO2 levels become toxic to humans.
Some people are bad with money and make stupid life decisions. No wage or training will fix it.
My office manager makes almost $75k, and financed a used car at 19% interest, even after I explained how to calculate the interest to her. She is 40 and a grandma. She gets a bonus and uses it to buy seasons pass at a theme park. I think a few country songs were written about her....
That actually isn't true. Bringing action against an employer is easy and free for the employee, and the penalties are severe. What the current system does is encourage employers to make their employees live in fear so they will be too intimidated to file an action-- battered wife syndrome essentially.
No clue how to improve it, but right now an honest, good faith mistake could bankrupt a company.
There are plenty of citizens who are afraid of reporting abuses. There are no simple solutions; the reality is that employers need to act ethically and morally in their treatment of employees. (Good luck with that.) Reality is that people take the easy way out and make decisions on short term outcomes only.
Raising the minimum wage hurts me as an employer, despite the fact that we don't pay anyone less than twice (California) minimum wage. The issue for us in making sure we can classify engineers as exempt (salaried) employees. Only employees at over twice the minimum wage are eligible to be exempt status, and it would mean that some entry-level engineers would need to be classified as non-exempt. This brings in the mandatory breaks, lunches, and workplace rules that are inappropriate for a professional environment.
Sure, you can say pay them more, but that really doesn't solve the problem; it just makes it unattractive to hire people that aren't stars. We can have some engineers that are mediocre; not all tasks need stars. Hopefully we can turn them into stars in time, but that requires some discount in pay to be attractive.
You have obviously never dealt with copier maintenance. You can make it break whenever you want; there is even a scheduling routine built into the system for the technicians. The only reason to sell the toilet will be the service contract...
Reverse power flow at the primary substation level is an issue, but even moreso is the idea that you push 4x the current during peak generating periods that you would normally consume.
To make distributed generation work you need: distributed energy storage; capacity-responsive demand; or a high level of diversity in sources. It is difficult to get the diversity with solar except in partly cloudy conditions during the day, and the economics of small wind turbines are difficult to reconcile.
It is hard for me to imagine how nuclear provides compatibility with renewable; the compatibility always comes in the form of energy storage which smooths out the load profile. The best use-case is to have enough batteries to supply your loads from late afternoon through bedtime, and switch to utility to bridge through the night, maybe with a little small-scale wind thrown in at night.
Most people under 50 today will have 40+ year working careers. Do you really want 20-30 different employers over that time?
My personal experience is everyone has a different timer inside, and tends to change jobs on 1.5-2 year, 4-5 year, or 7-10+ year cycles. It is hard for people to break those cycles. Shorter cycles tend to be more performance-based; getting caught over-selling capabilities, and longer cycles are more complacency. People that do project-based work are a little different in rationale, but same kind of timers.
My advice is generally to leave a bad work environment quickly, but try to improve the work environment first before giving up.
As an employer, I avoid people that jump around because it is too expensive to recruit, train, bring people up to speed, and phase them out. If I don't think someone will be around for at least 3 years then they face an uphill battle.
Best way of managing those issues I have seen is to project on a whiteboard, markup there, while someone independent is marking up the PDF files electronically. When the discussion is finished, project up the markup PDF.
I agree with the parent's general process, but I do have meetings each week myself with 30 attendees and quite literally a ream of paper printed for each person. The actual drawings aren't re-printed for each meeting, but an updated 75-page schedule, 150-page RFI log, and 200-page submittal log is provided to each attendee, along with about 25 pages of meeting minutes and current issues.
It is hard to have a more efficient set-up, as the meeting is basically a coordination meeting for 5 different paper-pushers from different companies. Paper quickly becomes the lowest-common denominator. (Really pissing me off is the fact that the three people from my company all need to scan the documents afterwards to pick up their individual notes!)
If I was running the meeting, I would require a 2-page summary from each paper-pusher on open items, and have a projector that can be used to provide additional information when needed. Distribute the whole package electronically before the meeting and let people figure out how the heck they want to deal with the information themselves.
Not sure if the math is as favorable if you look at the net present value of the incremental earnings. Looking at individuals though, if you are bottom quintile you might be able to get a job that isn't manual labor, arguably improving quality of life. Being a tradesman though likely pays off better.
An entry level candidate in my field of engineering should have a solid foundation from their BS to be able to understand basic theory and concepts. Our job is to train them from that foundation in our specific field; there are fewer than 500 people a year who graduate with sufficient education to really hit the ground running.
They should have also passed the first test in the Professional Engineering process which gives them a head start in their career.
Does anybody else think it is ironic that they use the total earnings rather than the NPV at age 18 for the discussion on STEM earnings?! The bottom line is likely that the marginal increase in earnings is likely insufficient to justify college attendance for the lower quintiles if you have to pay your own way vial loans.
As long as the purchaser was looking at the ratio of NPV of the future Bitcoin earnings to the cost to purchase and operate in $ to justify his purchase then there is no problem with asking for a refund. The exchange risk on the ratio of Bitcoin to USD is all on the buyer though.
What percentage of people use Netflix 24x7? How many different shows do most Netflix users watch? Caching 48-72 hours of entertainment during periods of low utilization makes the situation better for everyone. Think of it as demand-leveling.
It is all peak-period problems, not average bandwidth. Invariably we get downgraded to barely viewable overcompressed SD on Sunday nights. A local smart cache of the next 5 episodes of the 5-6 different shows we watch most often would likely eliminate 90% of the network usage. If enough people have them it would make it a non-issue for the telco.
It is important for it to be a network-based cache though, so it is device independent.
Not really. Consumer class service has traditionally had a contention ratio of 20:1, while Business class service is closer to 5:1. If you have a 20Mb link, you should be entitled to 1Mb minimum. You aren't restricted by the last mile, but the overall network today.
The issue comes down to contention ratios and peering. The last-mile ISPs don't want to peer with Netflix at a Hub level, they want to peer at a POP level, so they don't "waste" any of their backbone network between carrying Neflix traffic. Both parties are acting in their own self-interest.
Rationally, I have to think that when one service provider represents 10% or more of the traffic on a given network they should be doing something to address it, and the responsibility really falls on their shoulders and not the ISP.
Using Netflix as a simple example, all they would need to do to reduce their problem is offer a cache option on the end-user's network. It is less efficient than having it at the ISP's facilities, but it isn't all that complicated and the cost can be borne by the customer and improve sticky-ness. Right now, it is a pain in the ass to do things like a proxy to avoid the network saturation.